1 /*
2  * Copyright (c) 2020 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #ifndef GMID_H
18 #define GMID_H
19 
20 #include <sys/socket.h>
21 #include <sys/types.h>
22 
23 #include <arpa/inet.h>
24 #include <netinet/in.h>
25 
26 #include <dirent.h>
27 #include <poll.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <syslog.h>
31 #include <tls.h>
32 #include <unistd.h>
33 
34 #include "config.h"
35 
36 #ifndef INFTIM
37 # define INFTIM -1
38 #endif
39 
40 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
41 
42 /* large enough to hold a copy of a gemini URL and still have extra room */
43 #define PATHBUF		2048
44 
45 #define SUCCESS		20
46 #define TEMP_REDIRECT	30
47 #define TEMP_FAILURE	40
48 #define NOT_FOUND	51
49 #define PROXY_REFUSED	53
50 #define BAD_REQUEST	59
51 
52 #define MAX_USERS	64
53 
54 #define HOSTSLEN	64
55 #define LOCLEN		32
56 
57 /* RFC1034 imposes this limit.  63+1 for the NUL-terminator */
58 #define DOMAIN_NAME_LEN (63+1)
59 
60 #define LOGE(c, fmt, ...) logs(LOG_ERR,     c, fmt, __VA_ARGS__)
61 #define LOGW(c, fmt, ...) logs(LOG_WARNING, c, fmt, __VA_ARGS__)
62 #define LOGN(c, fmt, ...) logs(LOG_NOTICE,  c, fmt, __VA_ARGS__)
63 #define LOGI(c, fmt, ...) logs(LOG_INFO,    c, fmt, __VA_ARGS__)
64 #define LOGD(c, fmt, ...) logs(LOG_DEBUG,   c, fmt, __VA_ARGS__)
65 
66 struct location {
67 	char		*match;
68 	char		*lang;
69 	char		*default_mime;
70 	char		*index;
71 	int		 auto_index; /* 0 auto, -1 off, 1 on */
72 };
73 
74 struct vhost {
75 	const char	*domain;
76 	const char	*cert;
77 	const char	*key;
78 	const char	*dir;
79 	const char	*cgi;
80 	int		 dirfd;
81 	struct location	 locations[LOCLEN];
82 };
83 
84 extern struct vhost hosts[HOSTSLEN];
85 
86 struct etm {			/* extension to mime */
87 	const char	*mime;
88 	const char	*ext;
89 };
90 
91 struct mime {
92 	struct etm	*t;
93 	size_t		len;
94 	size_t		cap;
95 };
96 
97 struct conf {
98 	int		 port;
99 	int		 ipv6;
100 	uint32_t	 protos;
101 	struct mime	 mime;
102 	char		*chroot;
103 	char		*user;
104 };
105 
106 extern struct conf conf;
107 extern int exfd;
108 
109 struct iri {
110 	char		*schema;
111 	char		*host;
112 	char		*port;
113 	uint16_t	 port_no;
114 	char		*path;
115 	char		*query;
116 	char		*fragment;
117 };
118 
119 struct parser {
120 	char		*iri;
121 	struct iri	*parsed;
122 	const char	*err;
123 };
124 
125 enum {
126 	S_HANDSHAKE,
127 	S_OPEN,
128 	S_INITIALIZING,
129 	S_SENDING_FILE,
130 	S_SENDING_DIR,
131 	S_SENDING_CGI,
132 	S_CLOSING,
133 };
134 
135 struct client {
136 	struct tls	*ctx;
137 	char		 req[GEMINI_URL_LEN];
138 	struct iri	 iri;
139 	char		 domain[DOMAIN_NAME_LEN];
140 	int		 state, next;
141 	int		 code;
142 	const char	*meta;
143 	int		 fd, waiting_on_child;
144 	char		 sbuf[1024];	  /* static buffer */
145 	void		*buf, *i;	  /* mmap buffer */
146 	ssize_t		 len, off;	  /* mmap/static buffer  */
147 	DIR		*dir;
148 	struct sockaddr_storage	 addr;
149 	struct vhost	*host;	/* host she's talking to */
150 };
151 
152 enum {
153 	FILE_EXISTS,
154 	FILE_EXECUTABLE,
155 	FILE_DIRECTORY,
156 	FILE_MISSING,
157 };
158 
159 /* gmid.c */
160 
161 __attribute__((format (printf, 1, 2)))
162 __attribute__((__noreturn__))
163 void fatal(const char*, ...);
164 
165 __attribute__((format (printf, 3, 4)))
166 void logs(int, struct client*, const char*, ...);
167 void log_request(struct client*, char*, size_t);
168 
169 void		 sig_handler(int);
170 int		 starts_with(const char*, const char*);
171 int		 ends_with(const char*, const char*);
172 ssize_t		 filesize(int);
173 char		*absolutify_path(const char*);
174 void		 gen_certificate(const char*, const char*, const char*);
175 void		 mkdirs(const char*);
176 char		*data_dir(void);
177 void		 load_local_cert(const char*, const char*);
178 void		 yyerror(const char*);
179 int		 parse_portno(const char*);
180 void		 parse_conf(const char*);
181 void		 load_vhosts(void);
182 int		 make_socket(int, int);
183 void		 setup_tls(void);
184 int		 listener_main(void);
185 void		 init_config(void);
186 void		 drop_priv(void);
187 void		 usage(const char*);
188 
189 /* provided by lex/yacc */
190 extern FILE *yyin;
191 extern int yylineno;
192 extern int yyparse(void);
193 extern int yylex(void);
194 
195 /* mime.c */
196 void		 init_mime(struct mime*);
197 void		 add_mime(struct mime*, const char*, const char*);
198 void		 load_default_mime(struct mime*);
199 const char	*mime(struct vhost*, const char*);
200 
201 /* server.c */
202 const char	*vhost_lang(struct vhost*, const char*);
203 const char	*vhost_default_mime(struct vhost*, const char*);
204 const char	*vhost_index(struct vhost*, const char*);
205 int		 vhost_auto_index(struct vhost*, const char*);
206 int		 check_path(struct client*, const char*, int*);
207 void		 open_file(struct pollfd*, struct client*);
208 void		 load_file(struct pollfd*, struct client*);
209 void		 check_for_cgi(char *, char*, struct pollfd*, struct client*);
210 void		 mark_nonblock(int);
211 void		 handle_handshake(struct pollfd*, struct client*);
212 void		 handle_open_conn(struct pollfd*, struct client*);
213 void		 start_reply(struct pollfd*, struct client*, int, const char*);
214 void		 start_cgi(const char*, const char*, const char*, struct pollfd*, struct client*);
215 void		 send_file(struct pollfd*, struct client*);
216 void		 open_dir(struct pollfd*, struct client*);
217 void		 redirect_canonical_dir(struct pollfd*, struct client*);
218 int		 read_next_dir_entry(struct client*);
219 void		 send_directory_listing(struct pollfd*, struct client*);
220 void		 cgi_poll_on_child(struct pollfd*, struct client*);
221 void		 cgi_poll_on_client(struct pollfd*, struct client*);
222 void		 handle_cgi(struct pollfd*, struct client*);
223 void		 close_conn(struct pollfd*, struct client*);
224 void		 do_accept(int, struct tls*, struct pollfd*, struct client*);
225 void		 handle(struct pollfd*, struct client*);
226 void		 loop(struct tls*, int, int);
227 
228 /* ex.c */
229 int		 send_string(int, const char*);
230 int		 recv_string(int, char**);
231 int		 send_vhost(int, struct vhost*);
232 int		 recv_vhost(int, struct vhost**);
233 int		 send_fd(int, int);
234 int		 recv_fd(int);
235 int		 executor_main(int);
236 
237 /* sandbox.c */
238 void		 sandbox(void);
239 
240 /* utf8.c */
241 int		 valid_multibyte_utf8(struct parser*);
242 char		*utf8_nth(char*, size_t);
243 
244 /* iri.c */
245 int		 parse_iri(char*, struct iri*, const char**);
246 int		 trim_req_iri(char*, const char **);
247 
248 /* puny.c */
249 int		 puny_decode(const char*, char*, size_t);
250 
251 #endif